Lu Shiuan-Huei, Kuan Yi-Chun, Wu Kuan-Wen, Lu Hsuan-Yu, Tsai Yu-Lin, Chen Hsiang-Ho, Lu Tung-Wu
Department of Biomedical Engineering, National Taiwan University, Taipei City, Taiwan.
Taipei Neuroscience Institute, Taipei Medical University, Taipei City, Taiwan.
Front Aging Neurosci. 2022 Dec 13;14:950411. doi: 10.3389/fnagi.2022.950411. eCollection 2022.
Mild cognitive impairment (MCI) is considered a transitional stage between soundness of mind and dementia, often involving problems with memory, which may lead to abnormal postural control and altered end-point control when dealing with neuromechanical challenges during obstacle-crossing. The study aimed to identify the end-point control and angular kinematics of the pelvis-leg apparatus while crossing obstacles for both leading and trailing limbs.
12 patients with MCI (age: 66.7 ± 4.2 y/o; height: 161.3 ± 7.3 cm; mass: 62.0 ± 13.6 kg) and 12 healthy adults (age: 67.7 ± 2.9 y/o; height: 159.3 ± 6.1 cm; mass: 61.2 ± 12.0 kg) each walked and crossed obstacles of three different heights (10, 20, and 30% of leg length). Angular motions of the pelvis and lower limbs and toe-obstacle clearances during leading- and trailing-limb crossings were calculated. Two-way analyses of variance were used to study between-subject (group) and within-subject (obstacle height) effects on the variables. Whenever a height effect was found, a polynomial test was used to determine the trend. A significance level of α = 0.05 was set for all tests.
Patients with MCI significantly increased pelvic anterior tilt, hip abduction, and knee adduction in the swing limb during leading-limb crossing when compared to controls ( < 0.05). During trailing-limb crossing, the MCI group showed significantly decreased pelvic posterior tilt, as well as ankle dorsiflexion in the trailing swing limb ( < 0.05).
Patients with MCI adopt altered kinematic strategies for successful obstacle-crossing. The patients were able to maintain normal leading and trailing toe-obstacle clearances for all tested obstacle heights with a specific kinematic strategy, namely increased pelvic anterior tilt, swing hip abduction, and knee adduction during leading-limb crossing, and decreased pelvic posterior tilt and swing ankle dorsiflexion during trailing-limb crossing. The current results suggest that regular monitoring of obstacle-crossing kinematics for reduced toe-obstacle clearance or any signs of changes in crossing strategy may be helpful for early detection of compromised obstacle-crossing ability in patients with single-domain amnestic MCI. Further studies using a motor/cognitive dual-task approach on the kinematic strategies adopted by multiple-domain MCI will be needed for a complete picture of the functional adaptations in such a patient group.
轻度认知障碍（MCI）被认为是心智健全与痴呆之间的过渡阶段，常涉及记忆问题，在跨越障碍物时应对神经力学挑战时，这可能导致异常的姿势控制和终点控制改变。本研究旨在确定在跨越障碍物时，优势肢和非优势肢的骨盆 - 腿部装置的终点控制和角运动学特征。
12例MCI患者（年龄：66.7±4.2岁；身高：161.3±7.3厘米；体重：62.0±13.6千克）和12名健康成年人（年龄：67.7±2.9岁；身高：159.3±6.1厘米；体重：61.2±12.0千克）分别行走并跨越三种不同高度（腿长的10%、20%和30%）的障碍物。计算了优势肢和非优势肢跨越障碍物时骨盆和下肢的角运动以及脚趾与障碍物之间的间隙。采用双向方差分析研究受试者间（组间）和受试者内（障碍物高度）对这些变量的影响。每当发现高度效应时，使用多项式检验来确定趋势。所有检验的显著性水平设定为α = 0.05。
与对照组相比，MCI患者在优势肢跨越障碍物时，摆动肢体的骨盆前倾、髋关节外展和膝关节内收显著增加（P < 0.05）。在非优势肢跨越障碍物时，MCI组的骨盆后倾以及非优势摆动肢体的踝关节背屈显著降低（P < 0.05）。
MCI患者采用改变的运动学策略来成功跨越障碍物。患者能够通过特定的运动学策略，即优势肢跨越时增加骨盆前倾、摆动髋关节外展和膝关节内收，以及非优势肢跨越时减少骨盆后倾和摆动踝关节背屈，在所有测试的障碍物高度下保持正常的优势和非优势脚趾与障碍物之间的间隙。目前的结果表明，定期监测跨越障碍物的运动学特征以减少脚趾与障碍物之间的间隙或任何跨越策略变化的迹象，可能有助于早期发现单领域遗忘型MCI患者跨越障碍物能力受损。对于多领域MCI患者采用的运动学策略，需要进一步使用运动/认知双任务方法进行研究，以全面了解该患者群体的功能适应性。
